NEW YORK — At this point in his career, Roger Federer recognizes the importance of a little extra work.

That's why the owner of a record 17 Grand Slam titles, and the man who spent more weeks ranked No. 1 than any other, was out there on a U.S. Open practice court late Tuesday afternoon, putting in some training time shortly after finishing off a 6-3, 6-2, 7-5 victory over 62nd-ranked Grega Zemlja of Slovenia in the first round.

At 32, at his lowest ranking, No. 7, in more than a decade, coming off a stunningly early exit at the previous major tournament — one of a series of newsworthy losses lately — Federer is OK with making some concessions. He insists his passion for tennis is still there.

"I'm in a good spot right now," Federer said. "I want to enjoy it as long as it lasts."

Federer made it sound, though, as if it isn't as easy to enjoy things the way his results have been going.

Federer entered Tuesday 32-11, a .744 winning percentage that doesn't sound too bad, until you consider his career mark at the start of this season was .816, and he's had years where he went 81-4 (.953). and 92-5 (.948). He's only won one tournament in 2013, which would be great for some guys, but Federer topped 10 titles three times, and hasn't won fewer than three in any season since 2001.

"Clearly, when you win everything, it's fun. That doesn't necessarily mean you love the game more. You just like winning, being on the front page, lifting trophies, doing comfortable press conferences. It's nice. But that doesn't mean you really, actually love it, love it," said Federer, whose streak of 36 consecutive Grand Slam quarterfinals ended with a second-round defeat at Wimbledon against an opponent ranked 116th. "That maybe shines through maybe more in times when you don't play that well. For me, I knew it — winning or losing, practice court or match court — that I love it."

The victory took only 82 minutes for Djokovic, seeking his second title and fourth straight final at Flushing Meadows.

Among the women, No. 11 Sam Stosur, who won the 2011 U.S. Open, was eliminated 5-7, 6-4, 6-4 by 17-year-old American qualifier Victoria Duval, who is ranked 296th and never before had faced a top 20 opponent or won a Grand Slam match.

"I know she didn't play her best today, and this is the best I've played in my career, so I'm really excited," Duval told the Louis Armstrong Stadium crowd. "I just tried to stay in the moment."

No. 2 Victoria Azarenka, the 2012 U.S. Open runner-up and a two-time Australian Open winner, was to play in the night session.